T33 - Mammals Flashcards
What is the basic body plan of mammals?
Four legged terrestrial animals
Fill in this sentence: mammals are covered in _ _ _ _ and secrete _ _ _ _ through their _ _ _ _ _ _ glands
hair, milk, mammary
Where do the three middle ear bones of mammals come from?
“leftover” jaw bones
T/F: Because mammals release heat, they are exothermic.
FALSE. They regulate their own body temperature, and are therefore endothermic.
What two features of the mammal body contribute to a high metabolic rate?
- the four-chambered heart
- endothermy
What are the two parts of the mammal jaw joint?
dentary and squamosal
What are the three characteristics of human teeth? Hint: various teeth for various diets is one of them.
- variety of teeth
- occluding closely (contact with each other)
- two sets over their lifespan
What makes the brains of mammals different than other vertebrates of the same sized-body?
LARGER brains
secondary palate
the bone partition between the nasal and oral cavities, allows for simulatenous chewing and breathing
What are the identifying characteristics of monotremes, such as echinas and platypi?
- lay eggs
- provide milk to young
- no nipples
- have cloacas
shared, derived traits of marsupials AND eutherians include:
1. _ _ _ parous
2. _ _ _ provides initial nourishment to the embryo
3. post-birth nursing/nourishment through _ _ _ _ from _ _ _ _
- viviparous (give birth to live young)
- placenta
- milk, nipples
At what point do marsupial young crawl to their mother’s pouch?
after they had been born as partially-developed embryos
T/F: one of the shared, derived traits of marsupials is their intromittent organ, which differs from eutherians
FALSE. both sexes of marsupials have cloacas
What is the purpose of a marsupial pouch? not all species have it, what is the alternative in some species?
milk glands, nipples, protection for development.
some species have their young hang onto their fur
Which has the most complex placenta, monotremes, marsupials, or eutherians?
EUTHERIANS
monotremes DO NOT have placenta, marsupial placenta is simple because they birth partially-developed embryos to finish development in the pouch
T/F: instead of a cloaca, eutherians have separate urinary and anal openings
TRUE
clade afrotheria
african mammals that diversified in africa
clade zenathrea
mammals that evolved in south america
euarchontoglires
not associated with a particular geographic region,
includes RODENTIA and PRIMATES
laurasiatheria
Eurasian and North American diverse clades
Fill int he following shared, derived traits of primates:
1. hands and feet adapted for _ _ _ _
2. _ _ _ _ brain and _ _ _ _ jaws
3. _ _ _ _
4. complex _ _ _ _ _ behaviour, _ _ _ _ _ _ care
- grasping
- large brain, short jaws
- forward-facing eyes
- complex social behaviour, parental care
What are the three extant groups of primates?
lemurs/lorises/bush babies, tarsiers, and anthropoids
What is the difference between old world and new world monkeys?
- old world: first evolution, found in africa and asia
- new world: south america
what is another word for homonoids?
apes
